The Fair Work Ombudsman has commenced legal action against a Caltex franchisee in Sydney for allegedly falsifying records of the wage rates it paid to overseas workers.

Facing the Federal Circuit Court is owner and his company, who formerly operated a Caltex in Five Dock.

The Fair Work Ombudsman investigated the Caltex last year as part of a proactive compliance activity involving audits of 15 Caltex service stations nationally.

The activity was conducted in response to concerns about underpayments and other non-compliance issues within Caltex's network of franchisee-operated outlets.

The Fair Work Ombudsman issued Notices to Produce and the owner and his company provided a range of documents, including contracts of employment time-and-wages records, pay slips and earnings summaries for six employees.

All six of the employees were overseas workers and all but one was an international student.

Concerned that the documents provided did not accurately reflect the wage rates the company had paid to employees, earlier this year the Fair Work Ombudsman issued further Notices to Produce to one bank, a superannuation fund and the company accountant.

The information contained in the documents obtained through the further Notices to Produce was inconsistent with information that had been provided by the owner and his company.

The Fair Work Ombudsman alleges that the reason for the inconsistency is that the owner and his company falsified documents and records and unlawfully made use of them by providing them to the Fair Work Ombudsman.

It is alleged that the owner and his company also contravened laws requiring employers to issue employees with accurate pay slips within one day of pay day.

The absence of accurate time-and-wages records prevented the Fair Work Ombudsman from completing a full audit to determine whether employees at Caltex Five Dock had been paid their full lawful entitlements.

Fair Work Ombudsman Natalie James says legal action has been commenced because allegedly providing false information that frustrates attempts to check whether vulnerable employees have been paid correctly is very serious conduct.

The owner faces maximum penalties of up to $3600 per contravention and his company faces penalties of up to $18,000 per contravention.

A directions hearing is listed in the Federal Circuit Court in Sydney on December 21.

Ms James says employers should be aware that the Fair Work Amendment (Protecting Vulnerable Workers) Act 2017 has now come into effect, increasing the maximum penalties for conduct including deliberate exploitation of workers and false records.

"The maximum penalties available for some serious conduct that occurs today or in the future are now significantly higher than the penalties available to be imposed in matters such as this one, where the allegedly contravening conduct pre-dates the commencement of the Act," she said.

The Fair Work Ombudsman’s investigation relating to the Caltex network remains ongoing.

The Fair Work Ombudsman recently published an open letter to international students to encourage them to seek free help from the agency if they experience any issues while working in Australia.

"We are seeking to raise awareness among international students that in line with an agreement between the Fair Work Ombudsman and the Department of Immigration and Border Protection, you can seek our assistance without fear of your visa being cancelled, even if you’ve worked more hours than you should have under your visa," Ms James said.